


Mine, Yours, Ours

by ABrighterDarkness



Category: Marvel Cinematic Universe
Genre: Alpha Bucky Barnes, Alpha Steve Rogers, Alpha/Beta/Omega Dynamics, Angst and Feels, Feelings Realization, Getting Together, Multi, Non-Traditional Alpha/Beta/Omega Dynamics, Omega Tony Stark
Language: English
Status: Completed
Published: 2021-01-26
Updated: 2021-01-26
Packaged: 2021-03-12 02:00:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,523
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29002617
Author URL: https://archiveofourown.org/users/ABrighterDarkness/pseuds/ABrighterDarkness
Summary: Tony sat, stunned, probably gaping like a wide-eyed idiot. He supposed that was an understandable response to getting smacked directly in the face with everything he’d wanted and been so sure he wouldn’t get to have.
Relationships: James "Bucky" Barnes/Steve Rogers, James "Bucky" Barnes/Steve Rogers/Tony Stark
Comments: 4
Kudos: 111
Collections: Stuckony Love Letters





	Mine, Yours, Ours

**Author's Note:**

  * In response to a prompt by [Fearlesslexi](https://archiveofourown.org/users/Fearlesslexi/pseuds/Fearlesslexi) in the [Stuckony_server_love_letters](https://archiveofourown.org/collections/Stuckony_server_love_letters) collection. 



> Hello!! I hope that you enjoy this little Valentines gift! <3 <3
> 
> Prompts used:  
> Short Prompts (Stuckony):  
> 1). A/B/O au  
> 2). Soulmates AU  
> Long Prompts:  
> 1). Tony wants to be Bucky and Steve’s omega but he thinks they have another omega  
> 

Bucky sighed and tightened his hold around Steve’s shoulders as they curled comfortably and contentedly together in the safety of their own quarters, their own bed. Then, out of a habit once stolen but that had fallen seamlessly back into place as his memories slotted back into place, he ran the tip of his nose down from temple to cheekbone, pressing a soft kiss at the end. 

The move had always served dual purposes. The affection of it was obvious. But it had also been a subtle way of scenting, checking in and seeing if he could pick up the tells on where Steve’s head was at. If he was fevered or if subtle strain or irritation leaked into his scent that Bucky might be able to mitigate without getting Steve’s literal and metaphorical hackles up. 

Now, the familiarity of the motion was as grounding as it was affectionate and telling.

The other half of the familiar habit fell into place, when Steve’s head tipped to the side and affectionately nudged Bucky’s nose with his own and stole a sweet kiss. That had always been telling too. If Steve had worked himself into a mood, that second half didn’t happen. And if, when he was small, he hadn’t been feeling well but refused to say as much, his response generally spoke for him, sighing tiredly and just leaning his head against Bucky’s. 

Back then, though, it’d been a little different. It was perfectly acceptable for two unbonded alphas to share an apartment, times were tough and surviving more so. With as close as he and Steve had been since they were small, it hadn’t garnered much attention that they chose to stay close. That had only worked to their benefit, as far as Bucky was concerned. Because, no matter the designations, they’d belonged together. Still did.

But those affectionate gestures were strictly reserved for the safety of that tiny shared apartment, both staunchly unwilling to put the other at risk. Bucky could admit that it had taken him, both of them really, some time to adjust to the easy acceptance and freedom of being together visibly. Even if just in the safety of the Tower. 

But living in the Tower was the source of another change that neither he or Steve seemed to know what to do with. 

Bucky’s memory was pretty solid these days, removed enough from HYDRA and the chair, the wipes. Constant, close contact to the connection he’d always shared with Steve definitely hadn’t hurt the recovery process. So, he knew without question that he’d loved and belonged only to Steve well before either of them had settled into their secondary designations. Being fully presented alphas, rather than prepubescent alphas, hadn’t changed that in the least.

Yes, Bucky Barnes was an alpha. No matter who said anything to the contrary, he  _ had _ an alpha too in Steve Rogers. It was just as sure and right and true of a claim as any beta or omega would have right to. Steve was his.

And he didn’t doubt for a moment that the reverse was true for Steve as well. Bucky sure remembered hearing the words whispered softly, sometimes teasing, others taunting, in his ear. From before and from the present. Steve had always been very clear about his claim.

Though neither of them were willing to risk the other’s safety by making it permanent and therefore visible to any and all who chose to take a closer look. They’d talked about it often enough though.

Bucky’d gone on plenty of dates, back then. Pretty betas and omegas, dolled up and, admittedly, lovely. And, despite his smaller stature and the way history liked to paint him before the serum bulked him up, so had Steve.

It had all been for show. 

Especially since those double dates were never quite what they seemed. Bucky was always,  _ always _ out with Steve, their dates with each other. That suited everyone just fine. Their dates got to be taken out, shown off the way they deserved while knowing that they were, at least for the evening, safe to be themselves. Steve and Bucky were allowed the same freedom.

It had been as perfect as Bucky could have expected to have. 

Things changed though, as they tended to do with any passage of time. Bucky hadn’t noticed immediately. It hadn’t been quite so clear and obvious while he was amidst his own painful recovery. Steve had been every bit as dotting and indulgent as Bucky only belatedly recognized as typical. Quick to reassure, quick to hug and to hold, and just as quick to take a step back and give Bucky space when it was needed. 

Their relationship had recovered too. Strengthened and grown from the utter wreckage they’d both been reduced to. Just as solid and sure as it had been once upon a time. Maybe more so since it wasn’t quite as hidden as it had once been by necessity. It was better than he could have expected and more than he could have dreamed of having. Twice in a single lifetime.

But now, Steve was courting an omega. 

So subtly that Bucky wondered if he even realized what his behavior was saying. So shyly that Bucky really couldn’t attribute it to anything else. Always so quick to offer first go at whatever food happened to be made or ordered in for dinner. Carefully putting a plate together, along with one carefully handed off to Bucky, and hand delivering it when dinner was missed, even before he’d sit down with his own meal. Casual touch, intended to be comforting. Bashful smiles and playful banter. Cherry-red blushes when he was teased back.

His behavior toward Bucky hadn’t budged an inch. Steve still kissed him the same. Touched and loved him the same. Curled up with and around Bucky the same at night when they were finally alone. Was still the same, sweet as spun sugar, the way he got only with those closest to his heart. All evidence pointed directly to the fierceness that Steve had always had when he loved.

But Bucky couldn’t  _ not _ notice that Steve was quietly courting Tony Stark. Or the very obvious indications that Tony was just as oblivious to Steve’s actions as Steve seemed to be. The slight widening of his eyes, surprised by the fondness in Steve’s voice that Bucky knew intimately. The slight flush to his neck and ears, sometimes all the way through to his cheeks, when Steve did something especially sweet or kind. The flustered way he quickly excused himself under the guise of work-to-be-done.

Tony might be oblivious but he wasn’t uninterested, albeit incredibly guarded.

Even as Bucky considered the dynamics, he knew he wouldn’t be objective if he didn’t take into account that he’d been doing the same. 

Going out of his way to give Tony the opportunity to fiddle with his arm. Spending time in the workshop outside of work on the arm while carefully keeping his own discomfort at the appendage tucked away. Listening happily to the rambling utterances and indulging Tony’s eagerness to teach. The modern world. Whatever project Tony happened to be working on. Gentle teasing about the number of Steve’s drawings that had wound up taped around the workshop.

Artwork had always been Steve’s thing to gift, back when they didn’t have much else. That hadn’t changed and Bucky truly hoped  _ that _ never would. It was a little fitting that Tony would be the recipient of so many.

The playful, snarky banter that Bucky couldn’t help but engage in if only for the smirks and smiles. And occasionally a couple of those lovely blushes. Filling Tony’s time as surely as Steve was. Yeah, Bucky was just as guilty as Steve. Though, he was fairly sure none of them felt particularly guilty.

But it was something they’d need to discuss. At some point. If he recalled right, and he was sure he did, it wasn’t a conversation they’d ever thought to have. What they had, it had always been more than enough. They hadn’t entertained the idea of anyone else, omega or otherwise, back then. Not even to provide cover as they sought their own. 

But no one else had ever made everything inside Bucky scream that they belonged with him, the same way Steve did. 

That changed at some point and Bucky wasn’t able to place when it had. But now they were, individually, showing interest. Very blatantly regardless of both Steve and Tony’s apparent obliviousness.

Bucky sighed quietly and pressed in for another kiss, letting it linger when he felt the upturn twist of Steve’s lips. He pulled back just enough to rest their heads together and then hesitated, gathering the words he knew needed to be said but unsure how to broach the topic. Steve’s brow furrowed slightly as he noticed the pause. He shifted just slightly closer and tenderly brushed hair back out of Bucky’s face, tucking it tenderly behind his ear.

“What’s on your mind, Buck?” Steve asked.

Bucky chewed on his lip for a moment, taking a slow deep breath. Calming his anxieties with the long-loved, long-familiar scent of Steve. A scent that was rapidly twisting into concern the longer Bucky wavered. 

“I just think we need to have a talk,” he admitted. Steve tensed warily and Bucky let his hand stroke down Steve’s side soothingly. “Nothin’ bad, Stevie. I love you. If HYDRA couldn’t destroy that, don’t think there’s anything else in the world that could.”

“Okay,” Steve said, drawing out the word. “Then let’s talk. Whatever’s bothering you, Bucky, let’s get it out.”

* * *

Tony had known that he was setting himself up for a mess when he invited the Avengers to live in the tower. He’d been well aware that just the differences in conflicting tempers and personalities would be a massive adjustment with an astoundingly high probability of turning explosive. Add the varying designational challenges and Tony knew, he  _ knew, _ that it was inevitably going to blow up directly in his face. 

It had been a stupid decision. A stupid offer. And he would undoubtedly pay the price for it eventually. 

But they’d had nowhere else to go, had they? Tony had the space, more than enough of it. 

As far as he was concerned, there was no way that he could have anticipated how  _ easily _ everyone seemed to settle in. Not that there hadn’t been rough patches. There was no denying that the first few weeks had been trying enough to earn more than a few self-recriminating thoughts in the early morning hours, when Tony had secluded himself in the safety of his lab.

Despite their initial interactions, Tony quickly found a fast kinship with Natasha. He had even stopped expecting to regret it, regret letting her in again. He and Bruce thrived when they worked together or even just settled in for comfortable brainstorming and hypotheticals. 

Steve was the most difficult adjustment for Tony, personally. And, he had to admit that most of that had nothing to do with their early exchanges or Howard’s idolization of the man--though that was  _ some _ of it. It also wasn’t just because the man was striking, which he undeniably was. Or because of the warm scent that marked his presence that Tony had quickly decided he could easily grow addicted to, if he allowed himself. 

Which he wouldn’t. Shouldn’t. 

Either way.

Frankly, Tony had no clue why it was so difficult to jive with Steve as easily as he’d done with the rest of the team. 

He had no frame of reference as to how to handle the oddly thoughtful behavior that soon followed the alpha’s agreement to stay at the tower. 

The willingness to sit quietly in the lab, sketching away in that book of his, while Tony prattled on and on. Likely about things Steve didn’t give two shits about but, for whatever reason, was kind enough to pretend anyway. Bringing food with him, more often than not. Never for himself though. He politely declined any offers to share, insisting that Tony should eat. Playfully tacking on the ‘before you forget again’.

Or how nearly every time he left the lab, a torn out sheet from the sketchbook appeared on Tony’s desk, without him even noticing Steve approaching to set it there. Sometimes the bots. Sometimes Tony himself. If there was a day or two where drawings didn’t appear, a beautifully detailed one tended to show up sometime later. Tony had acquired quite the collection of Steve Rogers’ artwork over the year and change they’d all lived at the tower.

But  _ why?  _ Tony wasn’t ignorant or naive. He knew that in some definitions of the term, Steve’s treatment could be considered courting type behavior. But Steve was  _ Steve _ and Tony was Tony so that couldn’t be it. It made absolutely no fundamental sense whatsoever. They’d come a long way from snarling and growling, at each other's throats, back on the helicarrier. But better, and even friendly, was miles away from definite interest. 

No matter what that little voice in the back of his mind told him.

Steve certainly wasn’t meant to be Tony’s. 

All of it tapered, just slightly but noticeably, when Barnes-- _ Bucky-- _ came back into the picture. Anyone with eyes could tell that Steve was doing every little bit he could to help with the healing and recovery. 

The most enlightening thing about Bucky’s recovery though, in Tony’s opinion, was watching them together. As in  _ together. _

It was extremely obvious that the two alphas were meant to be solidly side by side in every way imaginable, regardless of what society still thought about their shared designations. Even their scents complimented so well, so seamlessly that it was almost like something just clicked when they were together. Tony had been mesmerized by everything Steve from the start but even he hadn’t noticed the subtle, missing notes in that delectable scent until it was right in front of him. 

Perfectly complete.

He hadn’t expected that. He hadn’t expected or braced for the sting either. But it did go a long way in silencing the urges, that voice that kept insisting on the misguided  _ meant to be.  _

For a while, anyway.

As Bucky improved, Steve picked back up on his attentive behavior like he’d never missed a beat. The couch in the lab regained its frequent sentry. Drawings and food make consistent appearances on his desk without Tony seeing them being placed. The soft, shy smiles that Tony loved more than he could possibly express were constant. As were the sheepish blushes when Tony bantered back without even pretending to hesitate.

And then Bucky began to join them. Quietly at first, hesitant almost. It only took spotting a couple poorly concealed winces before Tony leapt at the opportunity to offer his technological expertise. 

Maybe, just  _ maybe, _ he’d wanted the chance to show off. 

Just a little bit. 

But more than that, what was the point in having the knowledge and abilities to make things better if he didn’t offer when there was an obvious need? There was no reason that arm should be hurting the way it obviously was. And Tony could help. Could make it better. 

And then it was back. That quiet voice in his mind, the press of his  _ everything _ insistent that this, right here, was exactly where he ought to be. Where he was meant to be. And it was back with a possessive fierceness that often felt like it was stealing the breath right from his already weakened lungs. And if there was one thing Tony had always known about himself, had come to terms with years and years ago, it was that he was a greedy bastard. The pull he felt toward  _ both _ alphas was as insistent as it was undeniable.

He  _ wanted. _

He wanted more of the soft smiles and sweet treatment. The unexpected kindnesses that he’d come to crave. The banter and teasing. He wanted to be a part of the way they wound together so  _ perfectly right  _ and he  _ could be. _ Tony wasn’t sure if it was just his twisted mind’s insistence or if it was something real and true but Tony  _ knew _ that given just a chance he could fit with them. They could love him, if they just gave him a chance.

The fierceness of that want, how painfully present it was, was generally a sure sign that he really shouldn’t have whatever it was he wanted so badly. And Tony well knew that. Knew better than to hope or to wish that much.

Tony jolted as a plate of food settled next to him on the desk. He blinked in surprise and followed the plate to the hand that held it and up until he met too-familiar smiling, blue eyes. The hand that had placed the plate onto Tony’s desk shifted, landing lightly at the nape of Tony’s neck and squeezing gently.

“You okay?” Steve asked, brows furrowed in obvious concern.

“What?” Tony said dumbly, mind spinning at the gentle contact even though it was far from being anything out of the ordinary. “Yeah. Yeah, all good. Fine.”

Steve’s lips twisted into a small smirk and his expression softened. “If you say so,” Steve said lightly, glancing curiously at the projection in front of Tony. “What’re you working on today?”

“Suit upgrades,” Tony answered automatically though he didn’t bother looking back at the designs. He was perfectly content exactly where his eyes were, thank you very much.

“Do you got a minute?” Steve asked, withdrawing his hand then to run down the back of his own neck awkwardly. “Got something I’d like to run by you, if you don’t mind.”

Tony leaned forward and waved away the display with a deliberate swipe of his hand. He settled back into his chair and turned bodily to face Steve. “I’m all yours, Cap,” he said, tilting his head curiously to the side when Steve’s face flushed pink.

“Ah, right,” Steve said blankly and then cleared his throat. After a pause, he glanced around the lab and grabbed the nearest chair, dragging it close to the one Tony was seated. Steve slowly lowered himself into the chair, very obviously thinking hard.

Tony frowned at the unease all but radiating off of Steve and sat forward in his seat to rest a hand on Steve’s forearm. “Hey,” he said gently. “Whatever it is, we can figure it out. But I kinda need to know what the problem is before I can help fix it.”

Steve smiled that smile, the soft and sweet one that never failed to steal Tony’s breath. He visibly hesitated, then covered Tony’s hand with his own free one, slow enough that Tony had plenty of opportunity to withdraw from the touch if he wanted to. It was safe to say that Tony’s hand didn’t budge, though he sure thought his heart might try to break through the arc reactor with the way it kicked up at the gesture.

“That’s kinda the thing, I suppose,” Steve admitted, though he was looking down at their hands rather than meeting Tony’s eye. He licked his lips and shifted his hold on Tony’s hand until Tony’s was caught between both of Steve’s large hands. “Tony, Bucky and I’ve been talking. A lot and…” he sighed heavily and chuckled softly. “This is harder than I thought it would be,” he muttered and then took a deep breath, hands tightening around Tony’s one, yet still undeniably gentle. 

“Tony, if you’d be interested, if you’d consent to it, Bucky and I would love the chance to court you properly,” Steve said, tentative and hopeful yet somehow giving the impression that Steve had spent some time rehearsing those words in his mind. 

Tony sat, stunned, probably gaping like a wide-eyed idiot. He supposed that was an understandable response to getting smacked directly in the face with everything he’d wanted and been so sure he wouldn’t get to have.

“What?” he asked, barely over a whisper.

“A-and it’s entirely okay if you, if you don't,” Steve rushed to add. Whatever carefully practiced words he had planned, they were clearly out the window and Steve was fumbling freely through in his usual, albeit highly endearing manner. “It--we’re not exactly traditional. We know that. We won’t be angry or anything if you’d prefer we left things as they are. I swear.”

“You want me?” Tony asked faintly. “Me?”

Steve tilted his head in confusion and then smiled that smile again. “Of course we want you, Tony,” he said easily. “You’re... _ everything, _ aren’t you? Frighteningly intelligent, astoundingly kind with one of the biggest hearts I’ve ever known. You’re funny and sweet and-and gorgeous and...Tony, of  _ course _ we want you.”

Tony hesitated. The old adage about things seeming too good to be true ringing through his mind. “Bucky knows you’re here? About this?” Tony asked, eyes narrowing curiously.

“I wouldn’t do that to either of you,” Steve said, a little sharply. “I respect both of you too much to try playing any sort of games, I swear it.”

Tony nodded because, yeah, Steve really wasn’t the sort to play those sort of games. Twist up and mess with emotions that would only wind up with all of them hurt. That wasn’t his sort of play. But--

“Why isn’t he here, then?” Tony pressed.

Steve flushed again, eyes dropping back to their hands. “Bucky,” he huffed a quiet, sheepish laugh. “Bucky figured it out before I did, you know? That there was something building here, with me and you. Don’t know if you noticed but I can be a little blind to what’s right in front of me sometimes. He pointed it out, it’s how the subject came up to begin with. That, if he hadn’t come back, if he were really--” Steve shook his head sharply and cleared his throat, unable to finish that statement. “That maybe something more would have come of it.” 

“Think I knew though, even if it didn’t fully register,” Steve smiled, meeting Tony’s eye head on. “Felt it. That draw to you. Same as I’ve felt for Bucky since I was nothing more than skin, bones, and bad attitude.”

“What did you feel?” Tony asked, hesitantly, near desperate to hear the answer.

“Like you’re where I’m supposed to be, with you. Yours,” Steve answered quietly. “Like you’re supposed to be with me, mine.”

Tony swallowed thickly at the confession-like words. “Does he not--?”

“He does,” Steve assured. “He feels it too, wants you just as much, Tony. Believe me. We’d not be having this conversation if having it was going to hurt either of you. But that original foundation that we’ve spent the last two years building, you and I? That’s why Bucky thought you might prefer me to be the one to ask.”

Tony wasn’t sure what exactly his expression did but Steve’s turned contemplative. “JARVIS, can you please ask Bucky to come down to the lab?”

“Certainly, Captain,” JARVIS responded and then after a brief moment spoke again. “Sergeant Barnes will be there momentarily.”

“Thank you, JARVIS,” Steve said. Tony watched, still stuck in a state of overwhelmingly spinning thoughts and feelings, as Steve lifted his hand and pressed a firm kiss to his fingers. “You’ll see.”

It was only a few brief moments later that Bucky was let into the lab. Tony watched him approach, scanning the scene speculatively. No doubt taking in Steve’s firm hold on Tony’s hand and Tony’s wide-eyed expression and who knew what else. 

As he drew near, Bucky raised a hand to run affectionately over Steve’s hair, tugging gently at the strands. “Lose your words already, Stevie?” he asked fondly.

“Tony doesn’t believe that you and I are in agreement,” Steve said evenly. “That we both want and would like to court him.”

Bucky hummed thoughtfully, and nudged pointedly at Steve’s shoulders until he sat back into the chair. Bucky didn’t seem to even consider the movement before settling himself into Steve’s lap, the chair creaking under the strain. Steve huffed but shifted just enough to maintain his hold on Tony’s hand without jostling Bucky.

Tony wondered if it shouldn’t look utterly ridiculous. Two massive alphas piled onto a single office chair that really wasn’t meant for even  _ one _ person their size, let alone both of them. It just looked right though. Like everything else the pair did together, it just fit them and it worked. No matter how crazy it ought to look or be.

Bucky reached for Tony’s free hand, folding both of his own around the one, a mirror of the hand Steve still held. Tony swallowed thickly and breathed in slowly, allowing himself to subtly indulge in the way their scents mingled together just as right and perfectly.

“Tony,” Bucky said, low and soft. “Steve and I? We’d really like to do this right by you, if you’ll let us. Take you out. Spoil you a little. Or a lot, most likely.” He smiled then, just a slight upturn of his lips that was fond as it was teasing. “‘Cause, you see, I got this alpha of mine, he’s a needy thing. Got himself head over heels for this omega. Has a thing for spoiling. Being soft and sweet. He’s good at it too, but I think you’re already familiar with that.” 

“Thing about my alpha though?  _ His _ alpha’s got a thing for you, too. Might be just as smitten. Not quite as good at being soft but maybe wants to spoil the both of you just as much,” Bucky added, no less surety in the words despite the very evident vulnerability he seemed to be feeling.

“This is an utterly terrible idea,” Tony muttered under his breath, belatedly aware that both Steve and Bucky were enhanced, to include their hearing, and likely caught it. He cleared his throat a little awkwardly. “You’re sure?” He asked tentatively. “It’s not just the omega-nature thing?”

“We went this long without needing an omega, Tony,” Steve chastised gently. “We want you because you’re you. We’d still want you if it meant we were three alphas rather than two, that doesn’t play as big of a part as you’re giving it credit for.”

Tony wasn’t quite sure how to take that. On one hand, it was encouraging that he wasn’t just experimental. A trial run. But...he  _ was _ an omega. They hadn’t needed or wanted one with them before now, how likely was it that they’d only confirm that and Tony would be left right back where he started? 

“That being said,” Bucky interjected, shifting in such a way that drew a wince from Steve. “We do want you as  _ our _ omega. We want you. You being omega isn’t what drew us, can admit that much. That’s all you. But god, if you’d let us Tony? Think you could be happy with us.”

Steve’s hand tightened around his and Tony looked up at the urging. “Give us a chance to show you?” he asked quietly.

Tony exhaled slowly and then nodded. “Yeah, yes. Please,” he answered finally.


End file.
